4. Parenthood

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Thirty percent of women say they experience no sexual pleasure at all for the entire first year after giving birth. "Some of these women are still hormonally affected," Queen explains. "All of them, most likely, are suffering from exhaustion and stress." Few couples fully anticipate the true impact of having an infant around the house — a change which leads to a complete transformation of schedules, rhythms, intimacy, and activities that "takes a toll on the young dads as well." In her work as a sexologist, Queen says, "I talk to young mothers who tell me tales of exhaustion, plus occasionally the unbelievably insensitive husband."